Basically what the topic says. Anyone on here use them to help increase the MPG? When I used to drive a gas car I noticed a small difference but now that I drive a diesel truck, I use it just to keep the injectors clean...which should help with milage as well.

Many years ago there was on the market a friction-proofing additive Whyn... something, very thin substance liquid, made to add to engine oil.

I tried a can, very small can at that, my idle speed increased so much I had to make a reduced speed adjustment. No problems, but I just thought the product would thin out the oil texture too much, later did a quick oil change for lack of trust, still no problems, but I lacked trusting the product. Ran it 3 months in a 56 Merc... V/8.

I use 2 additives in rotation in both cars - Lucas top cylinder lube and good ol' Marvel Mystery Oil, not for MPG but for protection. I may be doing something right for a change - my 1972 MGB still runs like a l'il bear @ 205,000 mi., motor never apart :)

TOMB21144 writes: I used to use a product called Gasahol plus. It said an extra 5 MPG. I tried it on a 400 trip. The first 200 I got 18 MPG then I added it and got 23 MPG. It was then taken off the market. The reason given was that it was supposed to eat away the rubber hoses. I believe the oil companies didn't like the increase in mileage._____The product was probably mostly ethanol and it is a corrosive additive. Rubber has not been used for a very long time in fuel systems. Mostly, neoprene and silicone are used these days.

But high concentrations of alcohol can attack aluminum too as is summarized by a 2005 SAE paper:

In 1999, some Japanese fuel suppliers sold highly concentrated alcohol fuels, which are mixtures of gasoline and oxygenates, such as alcohol or ether, in amounts of 50% or more. In August 2001, it was reported that some vehicle models using the highly concentrated alcohol fuels encountered fuel leakage and vehicle fires due to corrosion of the aluminum used for the fuel-system parts. The Ministry of Economy, Trade and Industry (METI) and the Ministry of Land, Infrastructure and Transport Government of Japan (MLIT) jointly established the committee on safety for highly concentrated alcohol fuels in September 2001. The committee consisted of automotive technology and metal corrosion experts knowledgeable about preventing such accidents and ensuring user safety. Immersion tests were conducted on metals and other materials used for the fuel-supply system parts to determine the corrosion resistance to each alcohol component contained in the highly concentrated alcohol fuels. It was confirmed that each alcohol component contained in the highly concentrated alcohol fuels currently on the market causes corrosion of the aluminum generally used for automotive fuel-system parts.

I used to use a product called Gasahol plus. It said an extra 5 MPG. I tried it on a 400 trip. The first 200 I got 18 MPG then I added it and got 23 MPG. It was then taken off the market. The reason given was that it was supposed to eat away the rubber hoses. I believe the oil companies didn't like the increase in mileage.

You can "stick it to The Man" and get cheap uber-fuel efficiency with acetone mixed with the gasoline.______Sorry, articles like these are a dime a dozen and worth much less. I've never had a lot of respect for Mythbusters and Popular Mechanics derives revenue from sources that don't want people experimenting with the fuels they use. I'll take my experience over them any day.

All I have said is that acetone will not hurt a modern fuel system and whether it increases gas mileage will depend on the car. I would add that as fuel systems become more and more effective the advantages (if any) of using acetone should diminish. You won't find me changing my mind on this until I see real substance and neither of those sources are truly reliable.

Here are some comments that should be considered as well. Most of SNOPE'S comments (as referenced by RICK_EVANS' post) are wrong with regard to potential damage to fuel systems. He says that acetone is corrosive. That's only half the truth and half the truth is nothing but distortion. Ethanol is corrosive too and that's one reason most cars on the road can tolerate only about 10% of our gas being ethanol according to the OEMs. In contrast, a normal dosage of acetone is about 3 oz per 10 gallons. That's about 0.2% which is not going to hurt any modern day fuel system. I've been using acetone for over 9 years and have yet to have a problem.

Acetone's claim to fame is that it reduces the surface tension of fuel enabling it to disperse into the combustion chamber in smaller droplets which makes it easier to burn. The supposed consequence of this (I'm trying to keep it objective here.) is that there's a more complete fuel burn and therefore less fuel is needed to produce the same power.

Speculatively, the problem for acetone is that the emissions system doesn't know about acetone and when it detects the lean exhaust created by acetone, it richens the mixture to compensate. I say "speculatively" because those of us who use acetone believe this is why some see an improvement and some do not concluding that some emissions systems must monitor lean fuel exhaust more than others. We have no scientific or empirical evidence to support this but it seems logical.

To summarize, acetone will benefit some and won't help some at all. It all depends upon your car. To really know if acetone helps, you can't just put some acetone in the tank once. You have to develop a baseline and then see how subsequent MPG results after starting acetone compare.

One thing is for sure: Used properly, acetone poses no threat to anyone with a modern fuel system.

I've used top-end oil additive to small engine devices for keeping their carburetor diaphragms from drying out and shrinking when stored, also throttle shafts stay lubricated against excessive governor movement wear when running. I often get 15+ years of use from mower engines, no carb problems, then run a fuel system cleaner now/then mixed into gas supply, a minimum amount.

I Always pour the remaining amount of gas can fuel > (1/2 pint into jar and check for any dirt/moisture before refilling, often it is ok to use up also.

I don't mess with additives for gaining MPGs in any ECM controlled vehicles.